Abstract A developer solution for the development of photographic silver halide materials is disclosed comprising (1) an ascorbic acid type developing agent, and (2) a mixture of at least two 3-pyrazolidone type developing agents chosen from (a) 1-phenyl-3-pyrazolidone, (b) 1-phenyl-4-methyl-3-pyrazolidone), (c) 1-phenyl-4-methyl-4'-hydroxymethyl-3-pyrazolidone, (d) 1-phenyl-4,4'-dimethyl-3-pyrazolidone. In a preferred embodiment the ascorbic acid type developing agent is l-ascorbic acid or iso-ascorbic acid or a salt thereof, and the mixture of the 3-pyrazolidones consists of a mixture of 1-phenyl-3-pyrazolidone and 1-phenyl-4-methyl-3-pyrazolidone. The developer composition of the invention shows improved sensitometric stability against a pH decrease caused by exhaustive continuous processing without developer replenishment.
Photographic developing solution comprising : (1) an ascorbic acid type developing agent corresponding to general formula (I), or a salt of it : wherein X represents an oxygen atom or an imino group, and n represents a positive integer from 1 to 4, and R represents a hydroxy group when n is 1, and R represents a hydroxy group or a hydrogen atom when n is 2 to 4. (2) a mixture of at least two 3-pyrazolidone type developing agents chosen from the group consisting of : (a) 1-phenyl-3-pyrazolidone, (b) 1-phenyl-4-methyl-3-pyrazolidone, (c) 1-phenyl-4-methyl-4'-hydroxymethyl-3-pyrazolidone, (d) 1-phenyl-4,4'-dimethyl-3-pyrazolidone.
Claim 2
Dependent Claim
23 words
Developing solution according to claim 1 wherein said ascorbic acid type developing agent is l-ascorbic acid or iso-ascorbic acid or a salt thereof.
Claim 3
Dependent Claim
25 words
Developing solution according to claim 1 or 2 wherein said ascorbic acid type developing agent is present in a concentration between 0.1 and 0.6 mole/l.
Claim 4
Dependent Claim
29 words
Developing solution according to any of claims 1 to 3 wherin said mixture of at least two 3-pyrazolidone type developing agents is a mixture of 1-phenyl-3-pyrazolidone and of 1-phenyl-4-methyl-3-pyrazolidone.
Claim 5
Dependent Claim
32 words
Developing solution according to claim 4 wherein said 1-phenyl-3-pyrazolidone is present in a concentration between 0.1 and 2.0 g/l, and said 1-phenyl-4-methyl-3-pyrazolidone is present in a concentration between 0.1 and 5.5 g/l.
Claim 6
Dependent Claim
31 words
Method for developing an image-wise exposed photographic material, comprising a support and a silver halide emulsion layer, by means of a developer solution according to any of claims 1 to 5.
Claim 7
Dependent Claim
14 words
Method according to claim 6 wherein there is no replenisher for said developing solution.
Claim 8
Dependent Claim
26 words
Method according to claim 6 or 7 wherein the silver halide emulsion, present in said silver halide layer, contains at least 70 mole % of bromide.